LTT's main flaws seemd to have been that he could be reckless and overconfident. Now when that works you are the hero every one admires but when it goes wrong.... well in LTT's case its a very bad day.

We don't know how he was towards the end with his allies. Rand in the last book was pretty much an ass and could seriously have alienated a lot of his closest allies. LTT did not have Rand's mental issues but if he could rub people up the wrong way it might account for the female Aes Sedai not going along with his plan.

What I like about LTT was his resolve. As military chief he would have known exactly how bad things were for the light especially before the end and it seems pretty clear that the Shadow would have loved to give him the No 1 position. He could easily have bailed on the sinking ship that was the light and been assured of power, position and safety for his family (at least until the world was destroyed) but he stuck with it to the bitter end.

As for his plan to strike at SG for those who say it was foolhardy when the female AS rejected it in favour of the Choedan Kal LTT went along with the plan. It was only when the access keys were lost that he returned to his original plan. At that point in time given the military situation I don't think he had any other choice. It was probably better to at least try and snatch victory from defeat rather that wait for the inevitable. I suspect that everyone who went on that mission knew that even if things went well most if not all of them would not be comming home.

While we will never see it I would have loved if RJ had written a short passage showing LTT say an hour or two before he let the attack, saying good by to his wife and family.